BL1 pc multiplayer help

as many of you know borderlands has always had multiplayer issues but in the past me and my friend have been able to play with minimal issues. recently after getting to op8 on most the characters in bl2 we decided to go back to bl1 for a run with another mate of ours the only problem now is my friend is unable to press online game in his menu. he heres the sound but cannot press it. i cant join him either but am able to join others. he has tried reinstalling verifying game files. any help would be appreciated thank you